I am familiar with that machine having sold it many years ago. The problem is in the power button. The spring inside isnt making a good contact. This can happen over time, just like button switches used in todays electronics. Toggle switches also can have a problem not making a clean contact also. This can be heard by a " popping sound" or the toggle switch not working at all in it on posistion. To solve the toggle switch problem buy yourself some Static free contact and control cleaner. Spay it through the front opening of that toggle switch and work it up and down until the problem is sloved. I personally would turn the power off disconnect it from its power source and remove the cover. If you have the wood panels on the side remove them first. With the cover off I would spray that cleaner on all the contacts even the inside of the power button which could solve that problem also. In any event it shouldn't cost you more than an hours time for an authorized repair man to fix your power button issue.